Some factors in the development of the amphibian ear vesicle and further experiments on equilibration
Journal of Experimental Zoology
Associate Professor of Neurology at ihe Wistar Insrizure WITH SIX FIGURES I n a previous paper concerning experiments on the developing ear vesicle' it was shown that the group of cells forming the primitive epithelial ear cup or ear vesicle of the tadpole is specialized to that degree that although removed to an abnormal environment the cells still continue to differentiate themselves into a structure possessing many of the features of a normal labyrinth. Recently it has been shown by Lewis2
... n shown by Lewis2 that even earlier, while still an uninvaginated plate, the ear anlage is already capable of a certain degree of independent differentiation. I n the following paper additional evidence will be given of the high degree of developmental independence possessed by the early labyrinth cells. It will be pointed out that individual parts of the vesicle may develop independently of the rest of the vesicle. It will also be shown that the process of differentiation extends to the difference existing between a right and left-sided organ. A left ear vesicle transplanted into the empty pocket left by the removal of the right ear vesicle develops into a labyrinth that is perfect in general form and in its relations to the brain, with the exception that it maintains its left-sided character; the anterior semicircular canal is found on the caudal side toward the vagus group, while the posterior canal lies toward the eye, and likewise the lagena which 1 Streeter, G. L., '06: ZLewis, W. H., '07: Some experiments on the developing ear vesicle of the tadpole with relation O n the origin and differentiation of the otic vesicle in amphibian embryos. to equilibration.